Centrifugal metal-pipe mold



Jan. 13. 1925 1,523,021

' J. B. LADD CENTRIFUGAL METAL PIPE MOLD Original Fil d ly 12, 1922 2Sheets-Shee l Br Wye ATTORNEY Jan. 13. 1925. 1,523,021

J. B. LADD CENTRIFUGAL METAL PIPE MOLD 0rigina1 Filed July 12, 1922 2Sheets-Sheet 2 INVENTOH 7W I6.

ATTORNEY Patented Jan. 13, 1925.

STATES JAMES B. LADD, OF ARDMORE, PENNSYLVANIA, ASSIGNOR TO UNITEDSTATES CAST IRON PIPE & FOUNDRY COMPANY, OF BURLINGTON, NEW JERSEY, ACORPORA- TION OF NEW JERSEY.

CENTRIFUGALH METAL-PIPE- MOLD.

Application filed July 12, 1922, Serial No. 574,470. Renewed December 6,1924.

To all whom it may concern:

Be it known that I, JAMES B. LADn, a citizen of the United States ofAmerica, and resident of Ardmore, in the county of Montgomery, in theState of Pennsylvania, have invented a certain new and usefulImprovement in Centrifugal Metal-Pipe Molds, of which the following is atrue and exact description, reference being had to the accompanyingdrawings, which form a part thereof.

My invention relates to metal pipe molds such as are generally used inthe centrifugal casting of pipes. Such molds, which are cooledexternally, usually by a water jacket, have their interior surfacesubjected to great strains by reason of the alternate heating andcooling of the inside of the mold during the operations of castingpipes, the inside of the mold being, at the time of pouring, exposed tothe temperature of the molten iron while the outside of the mold remainsat all times much cooler and, in the case of water cooled molds, at atemperature probably not exceeding 200 F. In another application filedby me, on the 12 July 1922 Serial No. 574,469 I have described and shownas a means for obviating or diminishing the destructive strains of theinside of the mold, the formation on said inside of the mold of a seriesof narrow slots or grooves of such width that the molten metal evenunder the pressure exerted by the rapid rotation of the mold, would notpenetrate into the grooves, but which at the same time permit thesegments into which the inside of the mold is divided to expandseparately and thus avoid the great strains to which the uninterruptedsurface of the mold would be subjected. My present invention has for itsobject to further improve molds provided with internal slots by soconstructing them that they may be more easily cooled and so that theouter and cooler portion of the mold will offer less resistance to theexpansion of the inner portion than has heretofore been the case.Primarily, my object is to provide for the air cooling of such a mold,but my new mold may also be advantageously used with water cooling. Myinvention consists, generally speaking, in constructing a mcldwithnarrow slots formed on its inner surface and with transverselyrunningslots formed on its outer surface,

should extend close to the internal slots.

My invention will be best understood as described in connection with thedrawings in which- Figure 1 is a sectional view of my improved mold.

Figure 2 is a cross section of the mold on an enlarged scale.

Figure 3 is an enlarged view of a section of the mold, as shown in Fig.1.

Figure 4 is an enlarged view of a segment of the mold shown on the samesection as Fig. 3.

Figure 5 is a view generally similar to Fig. 3, but showing amodification.

Figure 6 is a view showing another modification.

Figure 7 is a sectional view of a modification.

Figure 8, a cross section on line 88 of Fig. 7.

Figure 9 is an enlarged view of a section of the mold shown in Fig. 7and Figure 10, a view showing a modification.

A, Fig. 1, indicates the mold, and B the ring at the smaller end of, themold for forming the end of the pipe, and C the core at the other end ofthe mold for forming the bell, A indicating the enlarged end of themold. Through the interior of the mold I form a series of symmetricallydisposed longitudinal slots indicated at D, D, etc. These must be sonarrow that the melted metal will not be forced into them when it ispoured into the mold and for this purpose, should not much exceed twohundredths of an inch, and should be between one hundredth and twohundredths of an inch in width. These slots will permit the metal in thesegments into which they divide the interior of the mold, to expand andcontract without exposing the interior of the mold, as a whole, todestructive strains. E, E, etc. are circumferential slots which may beand should' be quite broad and which, when the mold is to be air cooled,may and should intersect the longitudinal slots D, as indicated tilintersect the slots D, but be separated therefrom by a thin metal web,as indicated at G in Fig. 5. H

Instead of making the slots E parallel to each other as indicated in theother figures, these slots may consist of a helix 6, as indicated inFig. 6.

In Figs. 7 to 10, the mold A is shown as having interior circumferentialslots (Z and outer longitudinal slots e the slots intersecting eachother inFigs. 7 8 and 9, and being separated by a thin metal shell 9 asshown in Fig. 10. This construction is obviously an equivalent,generally speaking, for the first described construction.

It is obvious that my-construction provides for an energetic cooling ofthe mold as the exterior slots increase the cooling surface and bringthe cooling medium close to the pipe casting.

It is also obvious that my construction produces a mold that is free toex and and contract, both longitudinally-an circumferentially,regardless of the difference in temperature of interior and exterior ofthe mold because the interior slots permit of free expansion andcontraction ofthe in terior of the mold in one direction and theexterior slots permit free expansion in the other direction.

Having now described my invention, what I claim as new and desire tosecure by Let ters Patent, is:

1. A centrifugal metallic pipe mold haring narrow slots in its innerface and transversely running slots in its outer surface.

2. A centrifugal metallic pipe mold having narrow slots in its innerface and transversely running slots in its outer surface extendinginward to intersect the inner slots.

3. A centrifugal metallic pipe mold having longitudinal narrow'slot's inits inner face and circumferential slots in its outer surface.

4. A centrifugal metallic pipe mold having longitudinal narrow.slots inits inner face and circumferential slots in its outer surface extendinginward to intersect the longitudinal slots.

' JAMES B. LADD.

